Well - this is the process I ended up in... I am not saying that other processes will not succeed, but for me, this is the one that gave me a good bread.
Take about 100 ml of water out of the total measured 420 grams. Warm it up to about 45 deg C. (in a microwave, 20 second on full power should be enough). In a standard cup (~180 ml), take a teaspoon of flour, add the yeast, one or two teaspoons of warm water, and make a fine paste with a teaspoon. Add the remaining water, a teaspoon sugar, stir well. Cover and keep for 15 to 20 minutes. It should foam well. (if it doesn't, probably the yeast is bad)
Keep about 2 cups of white flour aside. Homogenize the remaining flour (dry mix well, using a sieve or other methods), and the improver, GMS powder.
In a large bowl, make a mix of the remaining water (the sugar and L-Ascorbic acid should be dissolved in this water first) and about 60% of the total flour (excluding the white kept aside), slowly adding water and flour stage by stage. Finish with the proven yeast. The result should be a very thick batter. Cover the bowl with a wet towel and a lid, keep for about 30 to 45 minutes. It should blow up to about double, we call this the sponge.
Add the remaining flour (not the white kept aside), and sprinkle salt. Fold in the flour into the sponge well using an appropriate spoon/knife. (I use the plastic scraper I got alongwith my Kenstar Mixie). After mixing well, the kneading process starts.
I do the basic kneading using dough hooks and a hand mixer (morphy Richards - 300W. The Philips one does not have enough power. If you don't own this, you can hand-knead, with some effort, and making your hands a little messy). Knead at slowest speed for about 3 minutes, add the ghee/oil, kneed for a further 5 minutes. The dough will have become very smooth, and will be sticking to the bowl in places. Add about 1 to 1.5 cups of the white flower and continue kneading till the machine starts protesting a little. Now turn it out to a wooden (or clean smooth surface) after dusting with flour, hand-knead for about 2-3 minutes. The result should be a smooth ball (atleast on the top surface). Lightly oil a large bowl, dump the ball in and roll it around to coat with oil, cover with a wet towel (not touching the ball, a lot of space on top), close with a lid and allow to rise for 45 minutes to 1 hour.
You will have used all the flour by this time, maybe about a tablespoon leftover. Leave it on the surface, we will need it shortly. The dough ball should feel like a chubby infant's bottom, if you got it right.
In about an hour the ball would have more than doubled in volume. Press with your fist firmly, in the center, all the way down. You will hear a whoosh, with escaping CO2. Press down the sides gently to recover the ball shape as much as possible. Turn it on to the floured surface. Using a pipe (tube) like tool, press down in the center of the ball to divide it into two. Finally cut and separate the two halves with a sharp knife (Do not pull apart). Now take each half, lay it on the board with the cut edge facing up, use your fist to flatten it into a rectancle about an inch thick. Now make a roll from the rectangle, starting with a short side. Roll with both hands, without pressing too much. Set it aside with the edge at the bottom. (about 10 minutes, a cool place, refrigerator is OK)
Get your bread pans ready (I use one with 23 cm length, 9 cm width and 10 cm height), lightly oil the pan on all sides. Take out the rolls from the fridge, roll each one a little more, keep the edge joint at the bottom, stretch the top of the ends and tuck it at the bottom to get a good shape, Put into the pans, cover with wet towel and allow to rise a second time. (about 45 minutes should do)
Meantime preheat your oven to 175 deg C, (I use a Morphy Richards OTG28 RSS, about Rs 5000/-) set the grill such that the pans remain in the middle, bake for 50~55 minutes.
When done, turn out the breads immediately onto a wire grill (there should be free space at the bottom), allow to cool. Slicing is best done after 24 hours to allow for moisture re-distribution. You will not be able to slice it at all for atleast 2 hours after turning out.
Enjoy!!